Screw press separators are utilized for separating liquid and solid material from one another for de-watering fibrous material, such as manure. Screen separators generally operate on a flooded principal where the interior chamber of a screen separator is flooded with manure/water mixture.
One common function with screen separators is that they operate on the principle of having an internal auger which is in close engagement with a conical screen-like mesh having a foraminous surface with a plurality of holes. However, with lower concentration of solids being passed through the system, present analysis indicates that any clearances between the outer surface of the auger and the interior surface of the cylindrical screen member can reduce the efficiency of the de-watering of the material passing therethrough. The pre screen separator described herein in one form is to be flooded for proper operation in order for the upper portion of the pre-separator to function. With this the pre-screen separator in place, the wipers automatically move downwardly through the coupler joint. As noted above, prior art separators do not operate effectively when wear occurs, such as when tolerance is lost and the separator when the augur can wipe the solids off the screen. When there is an excessive gap between the components of a separator fiber can build therebetween and the auger does not “wipe” away the fiber from the interior surface of the screen and “blinding” occurs.
With the preseparator device, the de-watered solids are transferred to the screw-press separator, increasing production of the lower piece by approximately double with a fractional of power usage, and further, the upper unit is more robust and self-adjusting where when the particles hit the foraminous frustoconical surface it is wiped away.
The mechanism described herein operates as a flooded system where one insert line is present and the other line continues back to the continuous pump where the upper separator is always being overfed. Any time the lower separator loses its tolerance there is a hard time separating and the volume goes way down where the wiping does not work and “fines” plug the holes down below where the screw press separator drops off significantly. This is typically in a slush barn. In a scrape barn with 8-10% solids there is a lot of fiber in the screw press separator portion and the wear issues are not as critical where there is sufficient fiber to scrape in a flush system. When the input material is, for example, only 1% solids the efficiency and performance of a screw press separator lowers particularly the screw press falls out of tolerance with the distance between the auger and the screen member. Therefore, increasing the solids ratio by feeding the system with higher percentage of solids, such as going from 1.5-3% allows the lower separator to operate much more efficiently to, for example, double the efficiency thereof.